Arnold Fields, head of the Special Inspector General for Afghanistan Reconstruction, defended his performance by citing his own impoverished childhood, saying it allowed him to identify with many Afghans. He pledged to ensure that the $56 billion spent since 2001 on repairing the war-torn country was not wasted.

He also said that his agency, known as SIGAR, had gotten off to a slow start because of funding delays. "I have built SIGAR from nothing but legislation," the retired Marine major general said.

He said he appreciated his chance to testify but added, "I wouldn't say it is a pleasure."

A bipartisan group of senators has pressed President Obama to remove Fields.

Sen. Claire McCaskill (D-Mo.), who chairs the subcommittee on contracting oversight, noted that the USAID inspector general has a $10 million budget for audits and investigations in Afghanistan and has recovered or saved $149 million. With total appropriations of $46 million, SIGAR has recovered or saved $8.2 million, she said.

"It's very hard for me to reconcile that a lack of funding has been your problem," McCaskill said.

Of the 34 audits SIGAR completed, just four involved specific contracts. Fields said he would put greater emphasis on auditing contracts.

"I just want you to follow the money," said Sen. Scott Brown (Mass.), the subcommittee's ranking Republican.

McCaskill also challenged Fields on his hiring of outside consultants to draft parts of the agency's quarterly reports and to monitor reforms after a peer review prompted Attorney General Eric Holder to consider suspending SIGAR's law enforcement powers.

The senator noted that Fields had employed Joseph Schmitz, the Pentagon's inspector general from 2002 to 2005, to see whether those reforms were in place. Fields said he had expected that former FBI director Louis Freeh would be working with Schmitz. Was Fields hoping that Freeh might reach out to the attorney general? McCaskill asked.

Fields denied that was the case. "It had nothing to do with influence," he said.

But Fields said he regretted hiring Schmitz.

"If I had an opportunity to do it all again, I probably would have made another decision," he said.